TY - JOUR
T1 - Cycle lemma, parking functions and related multigraphs
AU - Eu, Sen Peng
AU - Fu, Tung Shan
AU - Lai, Chun Ju
N1 - Funding Information:
S.-P. Eu is partially supported by National Science Council (NSC), Taiwan under grant 98-2115-M-390-002-MY3. T.-S. Fu is partially supported by NSC under grant 97-2115-M-251-001-MY2.
PY - 2010
Y1 - 2010
N2 - For positive integers a and b, an (a, b̄)-parking function of length n is a sequence (p1, . . ., pn) of nonnegative integers whose weakly increasing order q1 ≤ . . . ≤ qn satisfies the condition qi < a + (i - 1)b. In this paper, we give a new proof of the enumeration formula for (a, b̄)-parking functions by using of the cycle lemma for words, which leads to some enumerative results for the (a, b̄)-parking functions with some restrictions such as symmetric property and periodic property. Based on a bijection between (a, b̄)-parking functions and rooted forests, we enumerate combinatorially the (a, b̄)-parking functions with identical initial terms and symmetric (a, b̄)-parking functions with respect to the middle term. Moreover, we derive the critical group of a multigraph that is closely related to (a, b̄)-parking functions.
AB - For positive integers a and b, an (a, b̄)-parking function of length n is a sequence (p1, . . ., pn) of nonnegative integers whose weakly increasing order q1 ≤ . . . ≤ qn satisfies the condition qi < a + (i - 1)b. In this paper, we give a new proof of the enumeration formula for (a, b̄)-parking functions by using of the cycle lemma for words, which leads to some enumerative results for the (a, b̄)-parking functions with some restrictions such as symmetric property and periodic property. Based on a bijection between (a, b̄)-parking functions and rooted forests, we enumerate combinatorially the (a, b̄)-parking functions with identical initial terms and symmetric (a, b̄)-parking functions with respect to the middle term. Moreover, we derive the critical group of a multigraph that is closely related to (a, b̄)-parking functions.
KW - Critical group
KW - Cycle lemma
KW - Labeled rooted forest
KW - Parking function
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U2 - 10.1007/s00373-010-0921-1
DO - 10.1007/s00373-010-0921-1
M3 - Article
AN - SCOPUS:77952323085
SN - 0911-0119
VL - 26
SP - 345
EP - 360
JO - Graphs and Combinatorics
JF - Graphs and Combinatorics
IS - 3
ER -